This patch refactors the nsThread event queue to clean it up and to make it easier to restructure. The fundamental concepts are as follows:
Each nsThread will have a pointer to a refcounted SynchronizedEventQueue. A SynchronizedEQ takes care of doing the locking and condition variable work when posting and popping events. For the actual storage of events, it delegates to an AbstractEventQueue data structure. It keeps a UniquePtr to the AbstractEventQueue that it uses for storage.
Both SynchronizedEQ and AbstractEventQueue are abstract classes. There is only one concrete implementation of SynchronizedEQ in this patch, which is called ThreadEventQueue. ThreadEventQueue uses locks and condition variables to post and pop events the same way nsThread does. It also encapsulates the functionality that DOM workers need to implement their special event loops (PushEventQueue and PopEventQueue). In later Quantum DOM work, I plan to have another SynchronizedEQ implementation for the main thread, called SchedulerEventQueue. It will have special code for the cooperatively scheduling threads in Quantum DOM.
There are two concrete implementations of AbstractEventQueue in this patch: EventQueue and PrioritizedEventQueue. EventQueue replaces the old nsEventQueue. The other AbstractEventQueue implementation is PrioritizedEventQueue, which uses multiple queues for different event priorities.
The final major piece here is ThreadEventTarget, which splits some of the code for posting events out of nsThread. Eventually, my plan is for multiple cooperatively scheduled nsThreads to be able to share a ThreadEventTarget. In this patch, though, each nsThread has its own ThreadEventTarget. The class's purpose is just to collect some related code together.
One final note: I tried to avoid virtual dispatch overhead as much as possible. Calls to SynchronizedEQ methods do use virtual dispatch, since I plan to use different implementations for different threads with Quantum DOM. But all the calls to EventQueue methods should be non-virtual. Although the methods are declared virtual, all the classes used are final and the concrete classes involved should all be known through templatization.
MozReview-Commit-ID: 9Evtr9oIJvx
This change makes the code a little cleaner and reduces the number of
places we call PR_GetCurrentThread, which is important for Quantum DOM
scheduling work.
The conversion was largely automatic, via:
find netwerk/ -name \*.cpp | \
xargs sed -i -e 's/MOZ_ASSERT(PR_GetCurrentThread() == gSocketThread[^;]*/MOZ_ASSERT(OnSocketThread(), "not on socket thread")/'
and related invocations, with a few manual tweaks at the end.
NSPR_LOG_MODULES is deprecated.
Programs in the test directory still use PR_NewLogModule,
so NSPR_LOG_MODULES is accurate for them. Getting these
to link against libxul for LazyLogModule is still to do,
so leave those for now.
MozReview-Commit-ID: 3uMR3YPJyyi
Many places that (re-)declared gSocketThread already included
nsSocketTransportService2.h; we can delete the declaration for those
places. For all the other places, we need to include
nsSocketTransportService2.h.
Like the previous patch, this patch is a no-op change in terms of
functionality. It does, however, pave part of the way for forcing
clients of nsEventQueue to provide their own locking.
This variable is written on the main thread (where we can access prefs),
but read on the socket thread on every poll iteration to decide whether
we should record telemetry information. Making it atomic communicates
our intent to read/write the value on multiple threads without any
locking. Using relaxed memory consistency is just as efficient as what
we have today, and it does not seem terribly crucial whether the *very
next* poll iteration records telemetry once the pref is updated, or
whether we can eventually get the correct value on the socket thread.
The bulk of this commit was generated by running:
run-clang-tidy.py \
-checks='-*,llvm-namespace-comment' \
-header-filter=^/.../mozilla-central/.* \
-fix
This is straightforward mapping of PR_LOG levels to their LogLevel
counterparts:
PR_LOG_ERROR -> LogLevel::Error
PR_LOG_WARNING -> LogLevel::Warning
PR_LOG_WARN -> LogLevel::Warning
PR_LOG_INFO -> LogLevel::Info
PR_LOG_DEBUG -> LogLevel::Debug
PR_LOG_NOTICE -> LogLevel::Debug
PR_LOG_VERBOSE -> LogLevel::Verbose
Instances of PRLogModuleLevel were mapped to a fully qualified
mozilla::LogLevel, instances of PR_LOG levels in #defines were mapped to a
fully qualified mozilla::LogLevel::* level, and all other instances were
mapped to us a shorter format of LogLevel::*.
Bustage for usage of the non-fully qualified LogLevel were fixed by adding
|using mozilla::LogLevel;| where appropriate.
This is straightforward mapping of PR_LOG levels to their LogLevel
counterparts:
PR_LOG_ERROR -> LogLevel::Error
PR_LOG_WARNING -> LogLevel::Warning
PR_LOG_WARN -> LogLevel::Warning
PR_LOG_INFO -> LogLevel::Info
PR_LOG_DEBUG -> LogLevel::Debug
PR_LOG_NOTICE -> LogLevel::Debug
PR_LOG_VERBOSE -> LogLevel::Verbose
Instances of PRLogModuleLevel were mapped to a fully qualified
mozilla::LogLevel, instances of PR_LOG levels in #defines were mapped to a
fully qualified mozilla::LogLevel::* level, and all other instances were
mapped to us a shorter format of LogLevel::*.
Bustage for usage of the non-fully qualified LogLevel were fixed by adding
|using mozilla::LogLevel;| where appropriate.
This is straightforward mapping of PR_LOG levels to their LogLevel
counterparts:
PR_LOG_ERROR -> LogLevel::Error
PR_LOG_WARNING -> LogLevel::Warning
PR_LOG_WARN -> LogLevel::Warning
PR_LOG_INFO -> LogLevel::Info
PR_LOG_DEBUG -> LogLevel::Debug
PR_LOG_NOTICE -> LogLevel::Debug
PR_LOG_VERBOSE -> LogLevel::Verbose
Instances of PRLogModuleLevel were mapped to a fully qualified
mozilla::LogLevel, instances of PR_LOG levels in #defines were mapped to a
fully qualified mozilla::LogLevel::* level, and all other instances were
mapped to us a shorter format of LogLevel::*.
Bustage for usage of the non-fully qualified LogLevel were fixed by adding
|using mozilla::LogLevel;| where appropriate.
